target/linux/brcm63xx/patches-4.4/000-4.5-30-gpio-add-a-data-pointer-to-gpio_chip.patch

   1 From b08ea35a3296ee25c4cb53a977b752266dafa2c2 Mon Sep 17 00:00:00 2001
   2 From: Linus Walleij <linus.walleij@linaro.org>
   3 Date: Thu, 3 Dec 2015 15:14:13 +0100
   4 Subject: [PATCH] gpio: add a data pointer to gpio_chip
   5
   6 This adds a void * pointer to gpio_chip so that driver can
   7 assign and retrieve some states. This is done to get rid of
   8 container_of() calls for gpio_chips embedded inside state
   9 containers, so we can remove the need to have the gpio_chip
  10 or later (planned) struct gpio_device be dynamically allocated
  11 at registration time, so that its struct device can be properly
  12 reference counted and not bound to its parent device (e.g.
  13 a platform_device) but instead live on after unregistration
  14 if it is opened by e.g. a char device or sysfs.
  15
  16 The data is added with the new function gpiochip_add_data()
  17 and for compatibility we add static inline wrapper function
  18 gpiochip_add() that will call gpiochip_add_data() with
  19 NULL as argument. The latter will be removed once we have
  20 exorcised gpiochip_add() from the kernel.
  21
  22 gpiochip_get_data() is added as a static inline accessor
  23 for drivers to quickly get their data out.
  24
  25 Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  26 ---
  27  drivers/gpio/gpiolib.c      | 10 ++++++----
  28  include/linux/gpio/driver.h | 14 +++++++++++++-
  29  2 files changed, 19 insertions(+), 5 deletions(-)
  30
  31 --- a/drivers/gpio/gpiolib.c
  32 +++ b/drivers/gpio/gpiolib.c
  33 @@ -280,7 +280,7 @@ static int gpiochip_set_desc_names(struc
  34  }
  35
  36  /**
  37 - * gpiochip_add() - register a gpio_chip
  38 + * gpiochip_add_data() - register a gpio_chip
  39   * @chip: the chip to register, with chip->base initialized
  40   * Context: potentially before irqs will work
  41   *
  42 @@ -288,7 +288,7 @@ static int gpiochip_set_desc_names(struc
  43   * because the chip->base is invalid or already associated with a
  44   * different chip.  Otherwise it returns zero as a success code.
  45   *
  46 - * When gpiochip_add() is called very early during boot, so that GPIOs
  47 + * When gpiochip_add_data() is called very early during boot, so that GPIOs
  48   * can be freely used, the chip->dev device must be registered before
  49   * the gpio framework's arch_initcall().  Otherwise sysfs initialization
  50   * for GPIOs will fail rudely.
  51 @@ -296,7 +296,7 @@ static int gpiochip_set_desc_names(struc
  52   * If chip->base is negative, this requests dynamic assignment of
  53   * a range of valid GPIOs.
  54   */
  55 -int gpiochip_add(struct gpio_chip *chip)
  56 +int gpiochip_add_data(struct gpio_chip *chip, void *data)
  57  {
  58         unsigned long   flags;
  59         int             status = 0;
  60 @@ -308,6 +308,8 @@ int gpiochip_add(struct gpio_chip *chip)
  61         if (!descs)
  62                 return -ENOMEM;
  63
  64 +       chip->data = data;
  65 +
  66         spin_lock_irqsave(&gpio_lock, flags);
  67
  68         if (base < 0) {
  69 @@ -389,7 +391,7 @@ err_free_descs:
  70                 chip->label ? : "generic");
  71         return status;
  72  }
  73 -EXPORT_SYMBOL_GPL(gpiochip_add);
  74 +EXPORT_SYMBOL_GPL(gpiochip_add_data);
  75
  76  /**
  77   * gpiochip_remove() - unregister a gpio_chip
  78 --- a/include/linux/gpio/driver.h
  79 +++ b/include/linux/gpio/driver.h
  80 @@ -23,6 +23,7 @@ struct seq_file;
  81   * @dev: optional device providing the GPIOs
  82   * @cdev: class device used by sysfs interface (may be NULL)
  83   * @owner: helps prevent removal of modules exporting active GPIOs
  84 + * @data: per-instance data assigned by the driver
  85   * @list: links gpio_chips together for traversal
  86   * @request: optional hook for chip-specific activation, such as
  87   *     enabling module power and clock; may sleep
  88 @@ -92,6 +93,7 @@ struct gpio_chip {
  89         struct device           *dev;
  90         struct device           *cdev;
  91         struct module           *owner;
  92 +       void                    *data;
  93         struct list_head        list;
  94
  95         int                     (*request)(struct gpio_chip *chip,
  96 @@ -166,7 +168,11 @@ extern const char *gpiochip_is_requested
  97                         unsigned offset);
  98
  99  /* add/remove chips */
 100 -extern int gpiochip_add(struct gpio_chip *chip);
 101 +extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
 102 +static inline int gpiochip_add(struct gpio_chip *chip)
 103 +{
 104 +       return gpiochip_add_data(chip, NULL);
 105 +}
 106  extern void gpiochip_remove(struct gpio_chip *chip);
 107  extern struct gpio_chip *gpiochip_find(void *data,
 108                               int (*match)(struct gpio_chip *chip, void *data));
 109 @@ -175,6 +181,12 @@ extern struct gpio_chip *gpiochip_find(v
 110  int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 111  void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 112
 113 +/* get driver data */
 114 +static inline void *gpiochip_get_data(struct gpio_chip *chip)
 115 +{
 116 +       return chip->data;
 117 +}
 118 +
 119  struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 120
 121  #ifdef CONFIG_GPIOLIB_IRQCHIP